Together, the two companies are launching their products in the U.K., France, Germany and 9 other European markets, splitting the rights country by country and setting sights on a J&J drug that brings in roughly $2.3 billion on the continent each year. The antibody, which bears the generic name infliximab, targets the protein TNF and is approved to treat a wide array of autoimmune ailments including psoriasis, arthritis and inflammatory bowel disease.

The European launches herald a coming deluge of quasi-generic competition for blockbuster biotech drugs, as more and more top-selling therapies lose global patent protection over the next few years. According to a report from Allied Marketing Research, worldwide sales for copycat biologics will reach $35 billion by 2020 after scraping together just $1.3 billion in 2013. And the rise of copycat medicines is poised to save European health systems roughly $38 billion by 2020, Celltrion says.

The next and perhaps most profitable frontier for biosimilars is the U.S., which has lagged behind the rest of world in codifying a regulatory framework for the knockoff medicines. Hospira, soon to be a subsidiary of Pfizer ($PFE), is working with Celltrion to get a Remicade copy on the American market, preparing for a March 17 advisory panel meeting as it works to sway the agency.

Leading the charge in the U.S. is Novartis ($NVS), expected to win approval next month for a biosimilar of Amgen's ($AMGN) Neupogen, which boosts white blood cell production and is often used in tandem with chemotherapy. On its heels is Apotex, whose take on Neupogen is currently under FDA review, while Novartis' Sandoz, a global leader, is working up copies of Humira, Enbrel, Rituxan and Procrit. Hospira, thanks to a recent deal with Pfenex ($PFNX), is working on a version of Roche's ($RHHBY) blockbuster eye drug Lucentis, while Celltrion is working up biosimilars of the same company's Herceptin and Rituxan.

Express Scripts ($ESRX) has said the U.S. healthcare system could save roughly ​$250 billion over the next 10 years thanks to the rise of biosimilars, but bearish analysts caution there's no guarantee physicians will prescribe them interchangeably with their reference products. The performance of Remicade biosimilars in the major markets of France, Germany in the U.K. will likely provide some clues to the future in the U.S.